بهينه سازي رشد و توليد آنزيم كاتالاز در باكتري Kocuria sp. ASB 107 در محيط كشت هاي اقتصادي

Optimization of growth and catalase production in Kocuria sp. ASB 107 in economic medium

كاتالاز آنزيمي با توانايي تبديل H2O2 به آب و اكسيژن است. كاتالاز در صنايع مختلف به خصوص صنعت نساجي مورد توجه قرار گرفته است. در صنعت نساجي H2O2 به عنوان سفيدكننده استفاده ميشود. اين فرآيند در pH بالا انجام ميشود. بنابراين كاتالاز قليايي جهت احياي H2O2 بسيار مناسب است. باكتريKocuria sp. ASB 107 دارايمقدارزياديكاتالاز قليايي است . در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮاي دﺳﺘﯿﺎﺑﯽ ﺑﻪ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان رﺷﺪ ﺑﺎﮐﺘﺮي و ﺗﻮﻟﯿﺪ ﮐﺎﺗﺎﻻز از ﻣﺤﯿﻂ ﮐﺸﺖﻫﺎي ارزان ﻗﯿﻤﺖ ﻧﻈﯿﺮ ﻣﻼس ﭼﻐﻨﺪر ﻗﻨﺪ، ﻧﯿﺸﮑﺮ و آب ﭘﻨﯿﺮ اﺳﺘﻔﺎده ﺷﺪ. ﻣﻨﺤﻨﯽ رﺷﺪ رﺳﻢ ﺷﺪ و در اواﺧﺮ ﻓﺎز ﻟﮕﺎرﯾﺘﻤﯽ، ﻣﺤﺼﻮل ﺗﺨﻤﯿﺮ ﺳﺎﻧﺘﺮﯾﻔﯿﻮژ و ﻓﻌﺎﻟﯿﺖ آﻧﺰﯾﻤﯽ ﺑﺎ روش اﺳﭙﮑﺘﺮوﻓﺘﻮﻣﺘﺮي درﻃﻮل ﻣﻮج 240 ﻧﺎﻧﻮﻣﺘﺮ ﺑﺮرﺳﯽ ﺷﺪ. ﺑﺮاي ﺗﻌﯿﯿﻦ ﻣﯿﺰان رﺷﺪ ﺑﺎﮐﺘﺮي از وزن ﺑﯿﻮﻣﺎس ﺧﺸﮏ اﺳﺘﻔﺎده ﺷﺪ. ﺑﺎﻻﺗﺮﯾﻦ ﻓﻌﺎﻟﯿﺖ آﻧﺰﯾﻢ )U/mL 2136/25( و رﺷﺪ ﺑﺎﮐﺘﺮﯾﺎﯾﯽ )g/L 5/19( ﺑﺎ اﺳﺘﻔﺎده از ﻣﻼس ﭼﻐﻨﺪرﻗﻨﺪ )1 درﺻﺪ( و ﻋﺼﺎره ﻣﺨﻤﺮ )2/5 درﺻﺪ( ﺣﺎﺻﻞ ﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﺑﺎ 4 درﺻﺪ آب ﭘﻨﯿﺮ ﺑﻪ ﻋﻨﻮان ﻣﻨﺒﻊ ﮐﺮﺑﻦ ﻓﻌﺎﻟﯿﺖ ﮐﺎﺗﺎﻻزي و رﺷﺪ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﻪ ﻣﯿﺰان 3032/5 U/mLو 6/16 g/Lﻣﺸﺎﻫﺪه ﺷﺪ. ﻧﺘﺎﯾﺞ ﭘﮋوﻫﺶ ﻧﺸﺎن داد ﻣﻼس ﭼﻐﻨﺪرﻗﻨﺪ و ﻧﯿﺸﮑﺮ و آب ﭘﻨﯿﺮ ﺳﻮﺑﺴﺘﺮاﻫﺎي ارزان و ﻣﻨﺎﺳﺒﯽ ﺟﻬﺖ ﺗﻮﻟﯿﺪ آﻧﺰﯾﻢ و رﺷﺪ ﺳﻠﻮل ﻫﺴﺘﻨﺪ و ﻣﻨﺒﻊ ﻧﯿﺘﺮوژن ﻏﯿﺮآﻟﯽ اوره ﻣﻨﺎﺳﺐ ﻧﯿﺴﺖ.

Catalase is an enzyme capable of catalyzing the alteration of H2O2 to O2 and H2O. It has recently acquired importance due to its application in the textile industries. Kocuria ASB107shows relative high resistance against ionizing and UV radiation. the antioxidant barrier in this bacterium consists enzymes such as catalase. In order to achieve the highest rate of bacterial growth and catalase production, sugar cane molasses, sugar beet molasses and whey were used as cheap carbon sources. Growth curves were plotted and at the late logarithmic phase, fermentation product was harvested. Catalase activity was measured spectrophotometrically by monitoring the decrease in absorbance at 240 nm affected by the decomposition of hydrogen peroxide. bacterial growth was also stimated from the weight of dry biomass. The highest biomass (5.19 g/L) and catalase activity (2136.25 U/mL) were found in medium consisted 1% molasses and 2.5 % yeast extract. In addition with the 4% whey as a carbon source, catalase activity and growth were 3032.5 U/mL and 6.16 g/L respectively. The results showed molasses and whey are suitable and inexpensive substrate. on the other hand inorganic nitrogen sources such as urea are not suitable for the production of catalase and cell growth.